Sheet-like chemical cell, fuel cell and methods for manufacturing thereof

ABSTRACT

Disclosed is a sheet-like chemical cell including a plurality of unit cells each of which comprises an electrolyte membrane, a plurality of anode plates on one surface of the electrolyte membrane, and a plurality of cathode plates on the other surface of the electrolyte membrane, with the anode and the cathode plates opposed to each other in pairs with the membrane therebetween. Slots are provided in the electrolyte membrane between adjacent anodes and adjacent cathodes, and cathode and anode wiring layers, on thermoplastic sheets, are provided to sandwich the electrolyte membrane. forming a laminate. The laminate is heat-crimped, with wiring layers on both sides of the membrane being electrically connected through the slots, and thermoplastic resin, of the thermoplastic sheets, filling the slots. Also disclosed are methods of making such cells.

This application is a Divisional application of prior Application No.10/687,600, filed Oct. 20, 2003, the contents of which are incorporatedherein by reference in their entirety. Ser. No. 10/687,600 has issued asU.S. Pat. No. 7,323,266, issued Jan. 29, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a new sheet-like chemical cell and amanufacturing method thereof, a fuel cell and a manufacturing methodthereof.

2. Related Art

Thanks to the progress of recent electronic technologies, electronicdevices such as mobile telephone sets, book-type personal computers,audiovisual equipment, and mobile information terminal equipment havebeen downsized and become rapidly widespread as portable electronicdevices. Conventionally, such portable electronic devices are systemsdriven by secondary batteries. The secondary batteries have beendeveloping in the order of sealed lead-acid battery, Ni—Cd battery,nickel metal-hydride battery, and lithium-ion battery, that is, thanksto miniaturization, weight saving, and high energy density technologies.To prolong service lives of these secondary batteries by one charging,various improvements have been made such as development of batteryactivating materials and high-capacity storage structure to increasetheir energy densities.

However, the secondary batteries require recharging after a presetquantity of power is used and consequently, they require chargingdevices and comparatively long charging periods. The portable electronicdevices must solve these problems. The coming portable electronicdevices will require power supplies of higher energy densities andlonger running periods per recharging as they must process greateramounts of information at higher processing rates. In other words, theworld is expecting smaller power generators (or micro generators) thatneed no recharging.

As one of such power generators that meet the above requirements, a fuelcell power supply has been discussed. A fuel cell converts chemicalenergy of fuel directly into electric energy (electrochemically) andrequires no engine section although a conventional engine generator usesan internal combustion engine. Accordingly, the fuel cell has a highpossibility as a compact power generating device. Further, the fuel cellneed not stop the operation of the portable electronic devicetemporarily for recharging as frequently shown in the use of secondarybatteries as it keeps on generating power as long as fuel is supplied tothe fuel cell.

A polymer electrolyte fuel cell (PEFC) is well known as a high currentdensity cell to meet the above requirements. The PEFC comprises anelectrolyte membrane made of perfluorocarbon sulfonate resin, an anode,and a cathode and generates electricity by oxidizing the hydrogen gas atthe anode and reducing the oxygen gas at the cathode. To make this PEFCsmaller, for example, Japanese Patent Laid-open09-223507 discloses asmall PEFC power generating device comprising a cylindrical cellassembly which has an anode and a cathode respectively on the inner andouter surfaces of a hollow fiber electrolyte wherein hydrogen gas andair are supplied respectively to the inside and the outside of thecylinder.

However, as a hydrogen gas is used as the anode gas and its volumetricenergy density is low, the fuel tank must be greater when the small PEFCpower generating device is applied as a power source to a portableelectronic device. Further, this power generating system requiresauxiliary machines to supply fuel gas and oxidizing gas (e.g. air) tothe electrolyte membrane in order to maintain the performance of thecell. Finally, this makes the power generating system complicated and itcannot be said that the cell is small enough.

To increase the volumetric energy density of fuel, it is effective touse a liquid fuel and to simplify the cell structure (e.g. byeliminating the auxiliary machines to supply fuel and oxidizing agent tothe cell). For this purpose, some proposals have been made. JapanesePatent Laid-open 2000-26885 and Japanese patent Laid-open 2000-268836,which are the latest examples propose a direct methanol fuel cell (DMFC)which uses methanol and water as the fuel.

The DMFC comprises a liquid fuel container, a material, which can supplyliquid fuel by the capillary action on the outer wall of the container,an anode in contact with the material, a polymer electrolyte membrane,and a cathode, the members being disposed in that order. As oxygen issupplied by dispersion to the outer surface of the cathode, which is incontact with the outside air, this type of power generation device doesnot require any auxiliary machine to supply the fuel and the oxidizingagent. This simplifies the fuel cell system. The DMFC has a feature thatthe unit cells can be connected in series feature that the unit cellscan be connected in series simply by electrical connections and requireno cell connecting part such as a separator. However, when the DMFC isconnected to a load, the output voltage of a unit cell is very low (0.3to 0.4V). Therefore, to generate an output voltage available to portableelectronic devices, you must connect unit cells in series using aplurality of fuel tanks for the cells.

SUMMARY OF THE INVENTION

As described above, the conventional portable fuel cell comprises aplurality of unit cells each of which has the cathode placed on theouter surface and the anode placed on the inner surface. These unitcells are serially connected in the anode-to-cathode manner to generatea voltage available to portable electronic equipment. Further, theirmanufacturing method is very complicated and time-consuming because theunit cells must be electrically connected in series in theanode-to-cathode manner. As the number of unit cells to be connectedincreases, this problem becomes more distinct. Further in this case,each unit cell must be sealed to prevent leaks, which limits the packingdensity of unit cells. As the result, this limits the energy density ofthe cell.

Accordingly, it is an object of this invention to provide a sheet-likechemical cell of a simple and easy-fabricated structure having a smallquantity of parts that can improve the energy density strikingly, amanufacturing method thereof, a fuel cell, and as manufacturing methodthereof.

This invention is related to a fuel cell generating device whichcomprises an anode, an electrolyte membrane, and a cathode and generateselectricity by oxidizing the fuel at the anode and reducing the oxygengas at the cathode, particularly a fuel cell for portable electronicequipment which uses liquid fuel such as an aqueous methanol solution asthe fuel.

This invention relates to a sheet-like chemical cell or a sheet-likeelectrolyte-electrode cell assembly including a plurality of unit cellseach of which comprises an electrolyte membrane, a plurality of anodeplates which oxidizes fuel on one surface of said electrolyte membrane,and a plurality of cathode plates which reduces oxygen on the othersurface of said electrolyte membrane with said anode and cathode platesopposed each other in pairs with the membrane therebetween.

Further, the membrane has a plurality of slots each of which is providedbetween every two adjoining electrodes of the same type to electricallyconnect the opposing anode and cathode plates through these slots. Inthe completed electrolyte-electrode cell assembly sheet, these slots aresealed with an insulating material.

The fuel cell power generating device has this electrolyte-electrodecell assembly sheet with its anode side in contact with the fuel supplysection and uses liquid fuel, particularly aqueous alcohol solution asthe fuel.

This electrolyte-electrode cell assembly sheet is manufactured byforming a plurality of anode plates on one surface of the electrolytemembrane and a plurality of cathode plates on the other surface of theelectrolyte membrane, forming a slot between every two adjoiningelectrodes of the same type, electrically connecting the adjoining anodeand cathode plates with these slots, sealing these slots with aninsulating material, or sandwiching this electrolyte-electrode cellassembly sheet between two thermoplastic sheets having wiring layers onthem to electrically connect these wiring layers through slots on theelectrolyte membrane and fixing the sheets firmly by fusion-connectionof the plastic sheets.

The unit cells are electrically connected in series, in parallel, orboth to output desired high voltages and currents.

The fuel cell of this invention can run portable electronic equipmentsuch as mobile telephone sets, portable personal computers, audiovisualequipment, and other mobile information terminal equipment longer whenused as a battery charger to recharge the equipment while the equipmentis not running or as a built-in power supply instead of the secondarybattery, or continuously by replenishing the fuel.

The electrolyte-electrode cell assembly sheet of this invention has aplurality of electrodes on a single electrolyte membrane. They can bemanufactured by direct screen-printing on the electrolyte membrane orscreen-printing electrodes on a mold releasing film and transferringthem onto the electrolyte membrane by thermal compression using a hotpress and the like.

The anode catalyst constituting the power generation section can becarbon grains (carriers) impregnated with a mixture of platinumparticles and ruthenium particles or platinum-ruthenium alloy particlesand the cathode catalyst can be carbon grains (carriers) impregnatedwith platinum particles. These catalyst materials are easilymanufactured and available. However, the catalyst materials are notlimited. Any catalyst material can be used for anodes and cathodes ofthis invention as long as they are used for normal direct oxidation fuelcells. For stabilization and longer service lives, it is preferable toadd a third or fourth ingredient selected from a group of iron, tin, andrare-earth elements to the above precious metal components.

As this invention is not limited to the electrolyte membrane, a protonconductive membrane is also available. Typical membrane materials aresulfonated or alkylene-sulfonated fluorine polymers such asperfluorocarbon sulfonic acid resin and polyperfluorostyrene sulfonicacid resin, polystyrene, polysulfon, polyether sulfon, polyetherethersulfon, polyetherether ketone, and other sulfonated hydrocarbonpolymers. Among these electrolyte membrane materials, materials that hasa low methanol permeability are preferable because they can use fuelmore effectively without causing a cell voltage drop due to fuelcrossover.

It is also possible to make the fuel cell work in high temperatureranges by using a complex electrolyte membrane prepared by finelyimpregnating a thermo-stable resin with proton-conductive inorganicmaterial such as tungsten oxide hydrate, zirconium oxide hydrate, tinoxide hydrate, silicotungstic acid, silicomolybdic acid,tungstophosphoric acid, molybdophosphoric acid, etc. As long as anelectrolyte membrane has a high proton conductivity and a low methanolpermeability, the fuel utilization ratio of the fuel cell becomes high.Consequently, downsizing and long service life, which are the effect ofthis invention can be fully accomplished.

Generally, a hydration type acid electrolyte membrane is subject todeformation due to repetitive swelling (when the membrane is wet) andshrinkage (when the membrane is dry). Further it sometimes happens thatthe mechanical membrane strength is not enough when the electrolytemembrane has a high ion conductivity. To increase the mechanicalstrength of the electrolyte membranes and assure the reliability of thecell performance, various effective methods are available such aschemically bridging the electrolyte membranes, lining the electrolytemembranes with a woven or non-woven cloth having high mechanicalstrength and heat-resistance, or adding fibers of high mechanicalstrength and heat-resistance as a filler to the electrolyte membranes.

Further, this invention is characterized in that the electrolytemembrane sheet has a plurality of slots of a predetermined planar shapeon the sheet. Furthermore, this invention is characterized in that theplastic sheet has a plurality of wiring layers of a predetermined shapeformed at equal intervals thereon and that the wiring layers and thelayer areas of the sheet have a plurality of through holes thereon. Asexplained above, this invention provides new electrolyte membrane sheetsand new wiring sheets for a new fuel cell structure.

The power generation structure in accordance with this invention enablesrealization of a simple power generation system without any auxiliarymachine to supply fuel and oxidizing agent. Further, as the powergeneration system uses, as liquid fuel, an aqueous methanol solution ofa high volumetric energy density, the system can generate power longer(per container capacity) than the system uses hydrogen gas in a fuelcontainer of the same capacity. Furthermore, by replenishing the fuel,the system can generate power continuously without a break forrecharging from which a secondary battery cannot be free.

The fuel cell of this invention can run portable electronic equipmentsuch as mobile telephone sets, portable personal computers, portableaudiovisual equipment, and other mobile information terminal equipmentlonger when used as a battery charger to recharge the equipment whilethe equipment is not running or as a built-in power supply instead ofthe secondary battery, or continuously by replenishing the fuel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an electrolyte-electrode cell assemblyto which this invention relates.

FIG. 2 is a perspective view of an electrolyte-electrode cell assemblyto which this invention relates.

FIG. 3 is a perspective view of an electrolyte-electrode cell assembly,which is the first embodiment of this invention.

FIG. 4 is a cross-sectional view of the electrolyte-electrode cellassembly having wiring layers thereon in accordance with the firstembodiment.

FIG. 5 is a perspective view of the electrolyte-electrode cell assemblyhaving wiring layers thereon in accordance with the second embodiment.

FIG. 6 is a cross-sectional view of the electrolyte-electrode cellassembly having wiring layers thereon in accordance with the secondembodiment.

FIG. 7 is a perspective view of a set of a fuel cartridge and a fuelsupply section in accordance with the third embodiment.

FIG. 8 is a perspective view of a fuel cell in accordance with the thirdembodiment.

FIG. 9 is an exploded perspective view of a fuel cell in accordance withthe first comparative example.

FIG. 10 is a perspective view of the whole fuel cell in accordance withthe first comparative example.

DETAILED DESCRIPTION OF THE INVENTION DESCRIPTION OF THE PREFERREDEMBODIMENTS

In the following examples are described several preferred embodiments toillustrate this invention. However, it is to be understood that theinvention is not intended to be limited to the specific embodiments

Embodiment 1

FIG. 1 is a perspective view of an electrolyte-electrode cell assemblyto which this invention relates. A plurality of electrode plates 2 isformed on each surface of a single electrolyte membrane 1. FIG. 2 is anexploded perspective view of an electrolyte-electrode cell assembly ofFIG. 1. The electrolyte membrane 1 has a plurality of cathode plates 3that reduces oxygen on one surface of said electrolyte membrane 1 and aplurality of anode plates 4 which oxidizes fuel on the other surface ofsaid electrolyte membrane. These electrode plates can be manufactured bydirect screen-printing on the electrolyte membrane or screen-printingelectrodes on a mold releasing film and transferring them onto theelectrolyte membrane by thermal compression using a hot press and thelike.

The inventors formed anode plates (porous membranes) 4 of about 20microns thick on a polytetrafluoroethylene film by screen-printing aslurry comprising catalyst particles prepared by impregnating carboncarriers with 50% by weight of Pt—Ru alloy particles having 1 part ofplatinum and 1 part of ruthenium (in atomic ratio), 30% by weight ofperfluorocarbon sulfonic acid (Du Pont NAFION117) as a binder, and amixture of water and alcohol (20 parts water, 40 parts isopropanol, and40 parts of normal isopropanol by weight) as a solvent.

Similarly, we formed cathode plates (porous membranes) 3 of about 25microns thick on a polytetrafluoroethylene film by screen-printing aslurry comprising catalyst particles prepared by impregnating carboncarriers with 30% by weight of platinum particles, the electrolyte as abinder, and a mixture of water and alcohol as a solvent.

We prepared the catalyst particles by dispersing Pt—Ru alloy particlesand platinum particles of 5 nm in grain size over the surfaces of carbonparticles of 30 to 60 nm in grain size by electroless plating whilecontrolling the plating time, the reduction speed, and so on.

We prepared anode plates 4 (porous membranes) and cathode plates 3(porous membranes) by cutting out anode plates of 10 mm wide by 20 mmlong and cathode plates of 10 mm wide by 20 mm long respectively fromthe above polytetrafluoroethylene films, and removingpolytetrafluoroethylene films from the back of the plates. Then, we cutout a NAFION117 (trademark of DuPont for perfluorinated ion exchangemembranes) sheet of 70mm wide by 60mm long as the electrolyte membrane 1and placed eight anode plates in a 2 by 4 array at equal intervals onone surface of the cut-out NAFION117 sheet and eight cathode plates onthe other side of the NAFION 117 sheet in the similar manner with theanode plates and the cathode plates matched with the NAFION117 sheettherebetween as shown in FIG. 2. We sandwiched this electrode-membraneassembly between two 1mm-thick polytetrafluoroethylene sheets andhot-pressed this at 140° and about 5 MPa for 4 minutes. Afterhot-pressing thereof, we removed the polytetrafluoroethylene sheets andgot a sheet-like electrode-membrane assembly.

Embodiment 2

FIG. 3 is a perspective view of a sheet-like electrolyte-electrode cellassembly of Embodiment 1 which has slots 5 to electrically connect unitcells in series on the electrolyte membrane 1. As shown in FIG. 3, aslot is independently provided between every two adjoining electrodes ofthe same type on the electrolyte membrane 1. These slots also work toprevent short-circuiting of adjoining two electrodes by ions.

To electrically connect these unit cells in series, connect the upperunit cells from right to left using the slots, connect the leftmostupper unit cell to the leftmost lower unit cell using a slot betweenthem, connect the lower unit cells from left to right using the slotsuntil the rightmost lower unit cell is connected to the EXT terminal. Inthis case, three slots between three upper right unit cells and threelower right unit cells are not used for electrical connection and filledwith resin. Slots can be formed on the electrolyte membrane 1 before orafter the electrodes are formed.

FIG. 4 is a cross-sectional view of the electrolyte-electrode cellassembly showing how the unit cells are electrically connected in seriesusing current collecting plates. We disposed thin current-collectingplates 7 of a preset planar shape in place on the anode plates andcathode plates respectively with one edge of the current-collectingplate put in a slot between every two unit cells to electrically connecteach anode plate 4 to the next cathode plate 3 in sequence, filled theslots with an insulating sealing resin 6 to assure insulation of unitcells and to prevent fuel leaks, and covered the whole assembly with aplastic sheet.

With this, we obtained a sheet-like electrolyte-electrode cell assemblywhose unit cells are electrically connected. Each current-collectingplate 7 has almost the same planar shape as each electrode plate. Itsareas fit for the electrodes and the plastic sheets have finethrough-holes to flow fuel gases therethrough.

Embodiment 3

FIG. 5 is a perspective view of the sheet-like electrolyte-electrodecell assembly. We formed slots 5 (a slot between every two adjoiningunit cell electrodes) on the electrolyte membrane 13 of the sheet-likeelectrolyte-electrode cell assembly 17 of Embodiment 1 as shown in FIG.3 to electrically connect unit cells in series.

Then we took the steps of plating a copper conductive layer on separatethermoplastic sheets 11, 14 and a gold or platinum layer over the copperlayer, etching cathode wiring layers 12 of a preset planar shape to bematched with the aforesaid cathode plates 3, shown in FIG. 4, on one ofthe plated thermoplastic sheets to form a cathode wiring sheet 16,etching anode wiring layers 15 of a preset planar shape to be matchedwith the aforesaid anode plates 4, shown in FIG. 4, on the other platedthermoplastic sheet to form an anode wiring sheet 18, sandwiching thesheet-like electrolyte-electrode cell assembly 17 between these anodeand cathode thermoplastic sheets with the etched wiring layers matchedrespectively with the cathode and anode plates on the cell assembly 17,sandwiching this assembly between two polytetrafluoroethylene films, andhot-pressing thereof by a laminator.

With this, we got the sheet-like electrolyte-electrode cell assembly 17having wiring layers. Fine through-holes are made by punching or etchingon cathode wiring layers 12 on the cathode wiring sheets 16, anodewiring layers 15 on the anode wiring sheets 18, and the correspondingareas of the thermoplastic sheets to supply the fuel to the anode plates4 and oxygen to the cathode plates.

The cathode wiring layers 12 and the anode wiring layers 15 areconnected in series in the manner similar to the serial electricalconnection of FIG. 3. They are a little shifted from each other so thatthey may intersect and connect with each other in the slots when thesheets are attached together.

FIG. 6 is a cross-sectional view of the electrolyte-electrode cellassembly having wiring layers 12, 15 thereon. The cathode wiring layers16 and the anode wiring layers 18 are respectively formed on thethermoplastic sheets so that they may be overlapped with each other atthe slots 5 that are formed on the electrolyte membrane to electricallyconnect the abode plates 4 and cathode plates 3 in series. Whenhot-compressed by the laminator, the wiring layers are made in contactand connected with each other in the slots.

At the same time, the slots 5 are filled with resin of the thermoplasticresin layer 19. When the thermoplastic resin becomes cold and set, theupper and lower wiring sheets are bonded together and the wiring layersare connected firmly. At the same time, the thermoplastic resin works toinsulate the slots 5 and prevent leaks of fuel from the slots. Thisembodiment can make all electric connections at a time and bond thewhole peripheries of the wiring sheets together except the EXT terminalareas.

Embodiment 4

FIG. 7 is a bird's-eye view of a fuel supply section, which uses theelectrolyte-electrode cell assembly of this invention. The unit of FIG.7 comprises a fuel supply section 22 which supplies fuel to theelectrolyte-electrode cell assemblies equipped with wiring layers, areplaceable fuel cartridge 21 which stores fuel, and liquid pipes 25which connect the fuel supply section 22 and the replaceable fuelcartridge 21. The fuel supply section 22 contains a fuel cell assemblyof Embodiment 1 on each side of the fuel supply section 22.

The fuel supply section 22 contains a porous material to disperse liquidfuel uniformly by the capillary action and supplies liquid fuel to everyunit cell through the opening 24. The fuel supply section has anelastomeric seal 23 to prevent fuel leaks, an external anode terminal 27and an external cathode terminal 27′ to take out electricity from thefuel cell on each of the front and rear sides of the fuel supplysection. The fuel supply section also has a plurality of gas-liquidseparating membranes 26 on the sides of the fuel supply section toescape gas generated by power generation to the outside and prevent aninternal pressure rise as shown in FIG. 7. Each electrolyte-electrodecell assembly 30 on each side is bonded to the fuel supply section 22 atthe periphery by adhesives or hot-compression.

FIG. 8 is a birds-eye view of the fuel supply section on which the fuelcell assemblies are bonded. As shown in FIG. 8, the sheet-likeelectrolyte-electrode cell assembly 30 having wiring layers prepared byEmbodiments' 2 and 3 is bonded to each side of the fuel supply section22. We supplied an aqueous methanol solution containing 5% by weightmethanol to this cell assembly in which 16 unit cells were connected inseries. We obtained an output of about 150 mW and a voltage of 3.2 V.

COMPARATIVE EXAMPLE 1

FIG. 9 is an exploded perspective view of an example of conventionalfuel cell and FIG. 10 shows a bird's-eye view of the assembled fuelcell. In the conventional fuel cell, a unit cell uses oneelectrolyte-electrode cell assembly 36 and requires a sealing materialto prevent a fuel leak from the unit cell. Substantially, an elastomericsealer 35 is placed on the periphery of each side of theelectrolyte-electrode cell assembly. These unit cells are placed inplace in a cell storage container 41, electrically connected in seriesby interconnectors, attaching the diffusion layers 34 and the outputterminals 38, covered with cell fixing plates 32 , and fixed firmly withscrews having a ventilation hole 40.

As explained above, the conventional fuel cell has a complicatedstructure and lots of parts. Further, positioning of parts in the cellstorage container is very difficult. Incorrect part positioning causednot only a power reduction but also a fuel leak. With a supply of anaqueous methanol solution containing 5% methanol as fuel, theconventional cell having four unit cells connected in series outputabout 20 mW.

A fuel cell assembly in accordance with embodiments explained abovecomprises a plurality of unit cells each of which comprises anelectrolyte membrane having a plurality of anodes on one side of theelectrolyte membrane and a plurality of cathodes on the other side ofthe electrolyte membrane. This simplifies the fuel cell structure,reduces the number of parts, and facilitates assembling. As this alsofacilitates disassembling the fuel cell assembly, onlyelectrolyte-electrode cell assemblies can be easily taken out fromrecovered fuel cells for recycling of precious metals. The embodimentssimplify fuel cell structures and manufacturing processes and alsoprovides a compact power supply fit for portable equipment without anyauxiliary machine. This invention can also provide portable electronicdevices using such fuel cells.

1. A method for manufacturing a sheet chemical cell, comprising:preparing an electrolyte membrane sheet having a plurality of cathodeplates on one face thereof and a plurality of anode plates on a facethereof opposed to said one face, and having a slot at positions betweenevery two adjoining cathode plates of the plurality of cathode platesand a slot at positions between every two adjoining anode plates of theplurality of anode plates; laminating at least one thermoplastic sheet,having a cathode wiring layer on one face thereof, on said one face ofthe electrolyte membrane sheet, and laminating at least onethermoplastic sheet, having an anode wiring layer on one face thereof,on said face of the electrolyte membrane sheet opposed to said one face,in such a manner that the cathode wiring layer is in contact with thecathode plates and the anode wiring layer is in contact with the anodeplates; and hot-crimping a set of the electrolyte membrane sheet havingthe thermoplastic sheets laminated thereon, wherein the plurality ofcathode plates and the plurality of anode plates are at opposedlocations, on the one face and the face opposed to the one face, of theelectrolyte membrane sheet, wherein after said hot-crimping the slotsare filled with thermoplastic resin of the thermoplastic sheets, andwherein after the hot-crimping anode and cathode wiring layers areconnected via the slots.
 2. The method for manufacturing a sheetchemical cell of claim 1, said anode wiring layers and said cathodewiring layers are of the same planar shapes as those of said anode andcathode plates, respectively, with said anode and cathode wiring layersbeing matched with said anode and cathode plates to be in contact witheach other at slot positions, and wherein said hot-crimping includesfusion-bonding said wiring layers together through said slots so thatthe wiring layers are electrically connected in series.
 3. The methodfor manufacturing a sheet chemical cell of claim 1, wherein said methodfurther comprises forming said slots, and forming two thermoplasticsheets respectively having wiring layers of the same planar shapes asthose of said anode and cathode plates, with said wiring layers matchedwith the anode and cathode plates, and wherein said hot-crimpingincludes fusion-bonding said wiring layers together through said slotsso that the wiring layers are electrically connected in series.
 4. Amethod for manufacturing a fuel cell assembly, comprising the method formanufacturing a sheet chemical cell of claim
 1. 5. A method formanufacturing a sheet chemical cell of claim 1, wherein the anode platesare placed to be in contact with either or both surfaces of a fuelsupply section including a porous material which diffuses liquid fuel bycapillary action.